The short answer at this point is that we do not know and the Dish has learned not to speculate. We now have a graphic idea of whathappened – but no context to make sense of it. Until the full context emerges, we’re not guessing.

(Photo: Two blood stained feet of a man hangs outside an ambulance outside a medical tent located near the finish of the 117th Boston Marathon after two bombs exploded on the marathon route on April 15, 2013 in Boston, Massachusetts. By Jim Rogash/Getty Images)

If you’ve never run in, or even merely attended, the Boston Marathon, there are some unequivocal facts you should know. First, it’s an extremely open event, in the sense that the only thing separating you — well, you and a couple hundred thousand of your fellow spectators — from the planet’s most elite runners is usually nothing. Sometimes, it’s one of those easily moveable steel police barricades, sometimes it’s a piece of race tape, sometimes it’s the stern hand of a volunteer. But sometimes it’s nothing, and people are always running from one side of the course to the other. You have to time it like you’re running across the street in Rome. Runners come by out of nowhere and you don’t want to be the guy who accidentally tripped the lead runner when he was a mile or two from history.

Secondly, it’s more or less a mammoth, citywide party. The Red Sox play their annual Patriots’ Day game at 11:05 am, timed specifically so that three hours later, when the game ends, the crowd might file out to Kenmore Square and see a huge pack of participants run by on tired legs toward Copley Square and the finish line. A lot of people have a few drinks, which often leads to jokes about how easy it would be for any old spectator, to just tackle one of the lead runners at any time. But it never happened, because who would want to mess up the Boston Marathon? It was too much fun. You wouldn’t think standing there and watching people run — I mean, think about how that sounds — could be so much damn fun, but it always was.

Boston is a city particularly defined by its sports teams and sporting events, and the Boston Marathon is one of the most important of them, even if it doesn’t inspire the same local fervor as the Red Sox or the Patriots, though it does attract 500,000 spectators each year. The Boston Marathon is the oldest continuously-run annual marathon in the world, and the second-oldest footrace, inspired in its first year, 1897, by the marathon at the 1896 Olympics.

Once I got to Copley Square, I sat down and talked to an EMT. He had been one of the first on the scene. The problem the EMTs had was that the bomb went off inside the security barricades. The barricades meant to protect the spectators briefly prevented the EMTs from reaching the injured. This was not the last of the day’s cruel ironies. The EMT told me that the first person he saw was a 5- or 6-year-old with blood on his face. He did not seem to be in any way injured. One of his parents lay on the ground next to him. The parent wasn’t moving.

Marc Herman points out that “today’s attack at the finish line appears to have coincided with the moment when, statistically, the largest number of runners — and presumably their friends and family — would be nearby.” Nicholas Thompson zooms out:

There’s something particularly devastating about an attack on a marathon. It’s an epic event in which men and women appear almost superhuman. The winning men run for hours at a pace even normal fit people can only hold in a sprint. But it’s also so ordinary. It’s not held in a stadium or on a track. It’s held in the same streets everyone drives on and walks down. An attack on a marathon is, in some ways, more devastating than an attack on a stadium; you’re hitting something special but also something very quotidian.

If you are losing faith in human nature today, watch what happens in the aftermath of an attack on the Boston Marathon. The flood of donations crashed the Red Cross’s Web site. The organization tweeted that its blood supplies are already full. People are lining up outside of Tufts Medical Center to try and help. Runners are already vowing to be at marathons in the coming weeks and months. This won’t be the last time the squeakers run Boston. This won’t be the last time we gather at the finish line to marvel how much more we can take than anyone ever thought possible.

(Photo: Beacon Street near Kenmore Square remains empty for the use of emergency vehicles after two explosive devices detonated at the finish line of the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. By Alex Trautwig/Getty Images)

“I don’t know what’s going to be revealed to be behind all of this mayhem. One human insect or a poisonous mass of broken sociopaths. But here’s what I DO know. If it’s one person or a HUNDRED people, that number is not even a fraction of a fraction of a fraction of a percent of the population on this planet. You watch the videos of the carnage and there are people running TOWARDS the destruction to help out. … This is a giant planet and we’re lucky to live on it but there are prices and penalties incurred for the daily miracle of existence. One of them is, every once in awhile, the wiring of a tiny sliver of the species gets snarled and they’re pointed towards darkness.

But the vast majority stands against that darkness and, like white blood cells attacking a virus, they dilute and weaken and eventually wash away the evil doers and, more importantly, the damage they wreak. This is beyond religion or creed or nation. We would not be here if humanity were inherently evil. We’d have eaten ourselves alive long ago,” – Patton Oswalt.